Refactor/storage per session

[dushanlk]

• Refactored the existing in-memory database to create databases per user session.

How to try

1. For the initial request, trigger: http://localhost:8080/scrape?url=https://google.com
2. Subsequent pagination URLs will be generated with the session ID. ie: http://localhost:8080/scrape/<session-id>/<request-id>/<page>
3. To utilize the same session (same database) for subsequent new scraping requests, add the session_id query parameter to the URL. ie: http://localhost:8080/scrape?url=https://google.com&session_id=<session-id-from-prev-req>